The present invention is directed to override modes for flow control devices. More specifically, the present invention is directed to the use of a magnetically actuated sensor in the electronic expansion valve of an HVAC or refrigeration system and the initiation of an additional or override mode of operation responsive to the sensed magnetic field.
To position an electronic flow control device prior to installation of its main processor and its connective cabling is difficult since the main processor is used to implement the position of such a flow control device. Examples when it would be advantageous to implement pre-installation positioning occur during manufacturing tests of the device itself, during factory tests on the assembly line of the HVAC system, and at a job site after an HVAC system or refrigeration system has been installed but before the electronic controls are in place.
Additionally, a service technician initiating diagnostics or fault testing on an HVAC system having an electronic flow control device such as an electronic expansion valve may wish to initiate an override in the flow control device which either avoids the HVAC system controller or allows the technician to initiate the override remotely from the controller's operator interface.
There are various situations in the field where the owner of a system having a flow control device such as an electronic expansion valve may wish to manually control or override the operation of a flow control device.